DRG A NGT ARR, THE PLT WAS VECTORED FOR A LOC RWY 34 APCH. AFTER RCHG THE FINAL APCH FIX/OUTER MARKER (OM), HE WAS CLRD FOR THE APCH. ABT 5 OR 6 MIN LATER, THE ATC CTLR NOTICED THE ACFT WAS APRX 7 MI NW OF THE ARPT, CLIMBING ABV 3000' MSL. MISSED APCH PROCEDURE WAS TO MAKE A LEFT CLIMBING TURN TO 2000', PROCEED BACK TO THE OM & HOLD. WHEN QUERIED, THE PLT SAID THAT HE DID NOT SEE THE RWY. HE REQUESTED ANOTHER APCH & WAS VECTORED BACK TO THE OM, THEN WAS CLRD FOR A 2ND APCH.WITNESSES SAW THE ACFT MAKE A LOW PASS OVER THE RWY AT APRX 150' AGL. THE ARPT ELEV WAS 137'. MIN DSCNT ALT (MDA) FOR THE APCH WAS 600' MSL (900' FOR CIRCLING APCH). AFTER THE LOW PASS, THE ACFT ENTERED A RGT TURN TO THE EAST. (THERE WAS A WELL LIT INDUSTRIAL AREA APRX 1/2 MI EAST OF THE ARPT.) SUBSEQUENTLY, THE ACFT STRUCK TREES & CRASHED AT AN ELEV OF ABT 329. IT CRASHED APRX 2 MI EAST OF THE ARPT WHILE IN A RGT BANK & HDG 117 DEG. ABT 17 MI SOUTH AT EVERETT, THE 1645 WX WAS 100' OBSCD, 1/8 MI VIS WITH FOG; AT 1745, THE EVERETT WX WAS PTLY OBSCD, 5000' SCAT, 1-1/2 MI VIS WITH FOG.